DR. EMIL HOLUB. 191 



THE MIGRATION OF HIRUNDO RUSTICA TO 

 SOUTH AFRICA. 



BY DR. EMIL HOLUB, VIENNA. 



Iris commmonly known that the European Swallow winters 

 in Northern Africa, but it may be known to few that by far 

 the largest number of this species migrate to the southern 

 portions of the Dark Continent. 



Every year, from October to March, through the eleven 

 years of my sojourn in South Africa, and in the very midst 

 of the southern summer, I have seen these Swallows hunting 

 up and down the endless plains, destroying vast numbers of 

 the myriads of southern insects, and uniting every evening 

 into swarms of thousands, in some spots of hundreds of 

 thousands, to seek their resting-places for the night. 



In the following I will refer to one of those sleeping-places, 

 asking the kind reader to accompany me to that lonely spot, 

 visited by me on a day in November twenty-five years ago. 

 We are in the midst of an endless plain. Toward the east, 

 hardly perceptible by its treeless banks, the Harts Spruit * 

 takes its southwesterly course to the Vaal River, a right-hand 

 tributary of the Kai Gariep or Orange River, the latter in its 

 lower course being a natural boundary line of Cape Colony 

 toward the north. The grassy cover of the plain is about 



* A spruit is a river flowing after heavy rainfalls for a few days or 

 weeks only ; most of the year such a river is dry, with the exception of 

 some of the deepest places in its bed, which contain water for a few 

 months. 



